| 摘要 |
PURPOSE:To decrease an amplifier output to an optical signal power over a wide frequency range and then to prevent saturation of a post-stage circuit without deteriorating the S/N by adding a static capacitive element to other terminal of a photodetector. CONSTITUTION:A static capacitance of a capacitor Cp is selected to a value being several-several hundreds of multiple of a capacitance CPD of a photodetector. Moreover, resistors Rin and Rf act like the load for optical current detection and a resistor Rb acts like a resistor for setting a bias. Thus, the output amplitude of the amplifier is increased as a multiple of (1-CPD/CP) thereby preventing the saturation of the post-stage circuit. |
